Vapour Barrier Pan

ABSTRACT

A vapour barrier pan for use in building structures is provided. The pan is shaped to fit into the joist pocket located between subsequent joists of buildings. The pan central body comprises a top edge, two sides joined to the top edge generally perpendicularly, and a bottom edge joined to the two sides and parallel to the top edge. A centre crease is situated in between the two sides and extends from the top edge to the bottom edge. The centre crease instills flexibility into the pan body allowing it to be bent in order to fit into joist pockets of varying sizes. Alternatively, the pan can be cut along the centre crease separating it into two portions that can be overlapped to cover small joist pockets. The top edge and sides comprise flanges that extend outwardly in the same direction, with the flange for the top edge having a slit corresponding to the centre crease. Below the central body is a tab that can be situated under or over insulation installed in between wall studs under the joist pocket.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application No. 62/215,779 filed on Sep. 9, 2015, the contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

The field of the present invention relates generally to vapour barriers for use between floor joists of buildings.

DESCRIPTION OF THE PRIOR ART

For buildings constructed in colder climates it is necessary to consider the diffusion of moisture through a wall, ceiling, and/or floor assembly due to interstitial condensation. Interstitial condensation is the condensation that occurs within spaces inside the construction, as opposed to surface condensation. It occurs when warm, moist air penetrates inside a wall, roof or floor structure, reaches the dew point and condenses into liquid water. This moisture build up in the walls, notably within the insulation of walls, can allow mold growth, rotting of wood, corrosion of metal components and/or a reduction in the insulation's effectiveness. Apart from structural damage, this can lead to inefficient heating in homes causing an increase in heating costs.

To inhibit this, vapour barriers are used. Vapor barriers are placed over insulation in wall assemblies to inhibit the diffusion of vapour from the warm interior of the house into the walls.

The areas between floor joists, referred to as joist pockets, are particularly at risk of interstitial condensation. It is important to provide vapour barrier protection to insulation installed between adjacent floor joists but this is at times difficult due to the location and shape of joist pocket. During construction of buildings the joist pocket is filled with insulating material such as fiberglass. In order to provide a vapour barrier over the insulating material polyethylene sheet is stapled on top. However, this typically provides a very inefficient vapour barrier as working in such a tight space has proven to be difficult. Alternatively, paper that is cut into the shape of the joist pocket is used and placed in front of the insulation to act as a vapour barrier but this also provides a relatively weak barrier against vapour.

In an attempt to overcome some of the above limitations, Canadian patent 2,191,034 shows a vapour barrier panel having a body with top and side flanges to slide into position between floor joists. However, as the panel is rigid it can be seen that the panel cannot easily be fitted between the joists and is not able to accommodate the inevitable minor variations in joist spacing that occur during construction.

U.S. Pat. No. 4,972,635 shows a cant vent stop being made of a rigid moisture proof material that is folded to conform to the required shape. However, it will again be seen that the stop is preformed and thus will not facilitate fitting in joist pockets of varying sizes.

It is therefore an object of the invention to obviate or mitigate the above limitations.

SUMMARY OF THE INVENTION

In one aspect, there is provided a vapor barrier pan for use in a building structure comprising: a central body having a top edge, a bottom edge, and a pair of side edges extending between the top and bottom edges; a top flange extending from the top edge to engage an upper surface provided by the building structure; a pair of side flanges extending from the side edges for engaging substantially vertical laterally spaced surfaces provided by the building structure; and a tab extending from the central body from the bottom edge for engaging at least one lower surface provided by the building structure.

In an implementation, the pan further comprises a crease extending through the top flange, the central body, and the tab to enable the overall width of the pan to be adjusted by bending the central body about the crease. The crease can enable the pan to be bent in a forward direction or a rearward direction. The crease can also be adjacent at least one foldable portion of the central body to allow the width of the central body to be decreased or increased.

In an implementation, the tab can be generally L-shaped to enable the pan to be seated atop an upwardly facing one of the at least one lower surface and engage a forward facing one of the at least one lower surface. The tab can extend along the forward facing surface sufficient to enable a vapor barrier sheet to be attached thereto.

The pan can also include at least one adhesive strip along any one or more of the top flange, side flanges, or tab to provide a seal between the pan and the building structure. A backing comprising an insulative layer can also be provided.

In an implementation, the upper surface provided by the building structure is a subfloor situated atop a series of joists, the laterally spaced surfaces are provided by adjacent ones of the series of joists, and the lower surface is provided by a sill, the pan covering a joist pocket. The sill can be supported atop a basement foundation wall.

In an implementation, the pan is integrally molded from a material which has sufficient strength such that the flanges are self-supporting at right angles to the body and which material is impermeable to moisture. The flanges can also be tapered outwardly to permit stacking of a plurality of pans.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which

FIG. 1A shows a perspective view of a vapour barrier pan;

FIG. 1B shows an enlarged fragment of a portion of the vapour barrier pan labelled A in FIG. 1A;

FIG. 2 shows a cross sectional view of a building structure with a joist pocket;

FIG. 3 shows a front view of the vapour barrier pan of FIG. 1 situated in the joist pocket of FIG. 2;

FIG. 4A shows an alternate configuration of the vapour barrier pan of FIG. 1;

FIG. 4B shows the vapour barrier pan of FIG. 4A situated in a joist pocket narrower than that shown in FIG. 3;

FIG. 5 shows a further alternate configuration of the vapour barrier pan of FIG. 1 situated in a joist pocket further narrower than that shown in FIG. 4;

FIG. 6 shows a perspective view of an alternate embodiment of the vapour barrier pan of FIG. 1;

FIG. 7 shows a perspective view of a further alternate embodiment of the vapour barrier pan of FIG. 1;

The features of the invention will become more apparent in the following detailed description in which reference is made to the appended drawings.

DETAILED DESCRIPTION OF THE INVENTION

Turning to FIG. 1, a vapour barrier pan 10 is shown. In the preferred embodiment the pan 10 is used in the joist pockets formed in the basement level of buildings during their construction.

The barrier 10 comprises a central body 100 formed from a plastics material as discussed below. The central body 100 is generally ractangulated and is delimited by a top edge 102. A first side edge 104 forms a vertex with one end of the top edge 102 and a second side edge 106 forms a vertex with the other end of the top edge 102. A bottom edge 108 extends between the first side edge 104 and second side edge 106 and is generally parallel to the top edge 102. A length D1 for the pan 10 is measured as the distance between the side edges 104 and 106 respectively.

The central body 100 is formed with a crease 112 which extends between the top edge 102 and bottom edge 108. The crease 112 is situated midway between the first side edge 104 and the second side edge 106. The crease 112 thus defines a fold line and provides flexibility to the central body 100.

A top flange 114 projects perpendicularly outward from the central body 100 along the top edge 102. The top flange 114 has a slit 124 situated such that it aligns with the crease 112 and extends the width of the top flange 114 to separate the flange into two portions.

A first side flange 116 projects perpendicularly outward from the central body 100 along the first side 104. Similarly, a second side flange 118 projects perpendicularly outward from the central body 100 along the second side 106.

The top flange 114 is interconnected to the first side flange 116 at one end of its longitudinal side. At the opposing end the flange 114 is connected to the second side flange 118. It will also be appreciated that each of the top flange 114, first side flange 116, and second side flange 118 projects a similar distance outwardly from the same face of the central body 100.

A tab 110 extends laterally beyond each of the first side 104 and second side 106. The tab 110 is shaped as a step, defined by a first portion 120 which projects perpendicularly from the bottom edge 108 and a second portion 122 which extends generally perpendicularly below the first portion 120. The face of the second portion 122 is therefore generally parallel with the face of central body 100.

A slit 126 is present in the tab 110 separating into two equal portions similar to the top flange 114. The slit 126 is aligned with the central crease 112. Similarly, instead of a slit 126, the crease 112 can alternatively extend between the top flange 114 to the bottom of the tab 110.

As seen in FIG. 1B, a double sided adhesive 128 is coupled onto the outer face of the flanges 114, 116 and 118. The double sided adhesive 128 is covered by a removable layer 130. In the exemplary embodiment the adhesive 128 is a double sided tape and the removable layer 130 is a plastic sheet. Due to the presence of the slit 124 in the top flange 114, the strip of double sided adhesive 128 is discontinuous, and as such two strips of double sided adhesives 128 exist. One strip begins at the slit 124 and continues to the end of the side flange 116 while another strip begins at the other side of the slit 124 and continues to the end of the side flange 118.

As shown in FIG. 2, tab 110 projects to the same side of central body 100 as the flanges. However, it will be appreciated that the tab 110 can project on the opposing side of the central body 100.

The first portion 120 of the tab 110 is not attached to either flange 116 or 118, allowing it to be fixed relative to the central body 100. However, in alternate embodiments the first portion 120 of the tab 110 may be attached to the flange 116 on one end and the flange 118 on the other.

The vapour barrier pan 10 is molded integrally from a suitable material having impermeability towards vapour. In the exemplary embodiment the material used is polyvinyl chloride (PVC). However, it will be appreciated that other materials which can be used include polyethylene, aluminum foil, polystyrene, and asphalt coated kraft paper.

A conventional building structure 20 is shown in FIG. 2. The building structure 20 comprises a basement level 200 and a first floor 202. The basement level 200 comprises a basement wall 204 atop which lies a sill 206. The basement wall 204 is typically formed of concrete and the sill 206 is a wood member. The sill 206 supports a series of parallel floor joists 208 that are connected at their ends by a rim 210. On top of the floor joists 208 is a sub floor layer 212 made generally of plywood. The sub floor 212 provides the base for the first floor 202 having a wall assembly 213.

The space between the floor joists 208 can be referred to as a joist pocket 209. The joist pocket is enclosed by the adjacent floor joists 208 on each side, the sub floor 212 above, the sill 206 below, and the rim 210. It will be seen that the joist pocket 209 has an open face towards the interior of the basement level 200.

On top of the sub floor 212 is mounted a wall assembly 213 for the first floor 202, comprising a second sill plate 214 which supports a plurality of parallel vertical wall studs 216. An outer wall 218 is provided as an enclosure for the building structure 20.

Between the wall studs 216 is placed a layer of insulation 220. Exemplary material used for insulating material 220 includes fiberglass or cellulose. A polyethelene sheet 222 is then applied over the insulation and stapled to the wall studs to act as a vapour barrier for the wall assembly. To complete the wall assembly for the first floor 202, the sheet 222 is subsequently covered by a layer of drywall 224.

As shown in FIGS. 2 and 3, the pan 10 is placed into the joist pocket 209 such that each one of the first side flange 116 and second side flange 118 sits against a floor joist 208 and each second first portion 120 contacts the bottom surface of the sill 206 and the second portion 122 is underneath the sill plate 206.

A wall assembly constructed similar as described above may exist under the under sill 206.

During installation of the pan 10 into the joist pocket 209, the layer 130 is removed from the pan 10 exposing the adhesive 128. Next the pan 10 is moved into position so that the top flange 114 engages against the bottom face of subfloor 212. The flange 116 of the side 104 engages against the side face of a floor joist 208A, and the flange 118 of the side 106 engages against the side face of a subsequent parallel floor joist 208B. The pan is secured into place by ensuring there is proper contact between the adhesive 128 and surrounding surfaces.

With the pan 10 in place within the joist pocket 209, staples 300 are applied through the flanges of the pan 10 into the surfaces they contact to attach the flanges to the respective surfaces. The staples 300 are applied through the adhesive 128 to maintain vapor impermeability.

Once the pan 10 is in place, polyethelene sheet 222 is used to cover the wall assembly underneath the joist pocket 209 can be applied on top of the tab 110. It will be appreciated that the flap can be either above or below the polyethelene sheet 222. The polyethelene sheet 222 is secured to the tab 110 using, in one embodiment, a sealant (not shown) over which staples 300 can be applied. The tab 110 thus allows a continuous vapour barrier beginning at the joist pocket 209 and continuing to a wall assembly 213 below.

During installation, the central body 100 may be flexed about the crease 112 to reduce the width of the pan 10 in order to compensate for slight variations in the spacing of the joist. As the crease 112 allows for flexibility in the central body 100, the pan 10 can either be flexed forward as seen in FIG. 4A or backwards (not shown) about the crease 112. It will be seen that due to the presence of the slit 124 in the top flange 114, portions of the top flange 114 may overlap when the pan 10 is bent forward. Alternately, when bent in the opposing direction the portions of the top flange 114 may become spaced from one another. Similarly due to the presence of the slit 126 in the tab 110, portions of the top portion 120 may overlap or become spaced when the pan 10 is flexed forward or backwards respectively.

The flexing or bending of the pan 10 about crease 112 effectively reduces the distance between the two side edges from the original length D1. This in turn reduces the difficulty of installing the pan 10. As shown in FIG. 4B, the pan 10 can now be placed into the pocket 209 having a spacing D2. It will be appreciated that the length of spacing D2 is shorter than the length D1 of the pan 10.

When flexed about the crease 112, the layer 130 can be removed to expose the adhesive 128. Once the pan 10 is in the joist pocket 209, it can be flexed back towards its original configuration wherein the adhesive 128 contact the faces of joists 208 as discussed previously. The pan 10 can then be secured to the joist pocket 209 in a fashion similar to that discussed above.

Alternatively, the crease 112 defines a guideline for easily cutting the pan 10 into two sections.

As seen in FIG. 5 pan 10 is placed into a pocket 209 having a length D3 which is considerably shorter than the width D1 of the pan 10. To install the pan 10 into the joist pocket having a length D3, the pan 10 can been cut into two portions. These two sections, 10A and 10B, are overlapped wherein a portion of the section 10A is overlapped onto the section 10B or vice versa. A secure adhesive 500 such as aluminum tape or any other adhesive having impermeability to vapour can be applied over the overlapped portion 502 to ensure a proper seal.

In an alternative embodiment, shown in FIG. 6, a vapour barrier pan 60 has an accordion 600 present in the middle of the central body 100. It will be appreciated that the cease 120 is still present as discussed earlier. The accordion 600 is formed from a plurality of folds 602 in the material of the central body 100. Slit 124 is also present in the top flange 114 as well as slit 126 in the tab 110.

In the installation of the pan 60, the length of the body 100 can be extended or compressed by opening of closing the accordion 600 further. This extension or compression is achieved by moving the folds 602 in the according 600 further apart or closer together respectively.

During installation, the pan 60 it is brought to the pocket 209 as previously discussed and the pan 60 is extended or compressed as necessary to provide a better fit into the pocket 209. Then pan 60 is then inserted into the pocket 209 and secured to the surfaces as discussed. In exemplary embodiments five instances of the fold 602 exist in the pan 60 but it will be appreciated the number of folds can be increased or decreased without departing from the principles discussed herein.

In a further embodiment shown in FIG. 7, a vapour barrier pan 70 is shown. In the embodiment has a backing 702 is applied to its rear face 700. The backing 702 can be made of a material to provide further insulation to the joist pocket 209. The backing 702 can be permanently affixed to the rear face 700 of the pan 70 using a strong adhesive. Exemplary materials for the backing 702 include aluminum, felt, or other insulating materials. It will also be appreciated that the crease 112 is still present to instill flexibility discussed previously into the pan 70 having a backing 700. The pan 70 may also include the flanges discussed above as well as the crease and slits.

The flanges are preferably tapered at slight angles outwards relative to a plane directly at right angles to the central body 100 with the taper being sufficient to allow stacking of the pans with the flanges of subsequent pans in contact with each other and the central body 100 of subsequent pans in front of one another. Furthermore, during storage of the pan 10 it will be appreciated that the crease 112 can be used as a fold line to fold and compactly stow away the pan 10.

It can be seen that the pan 10 can alternatively be formed form a plurality of materials joined together. The different portions of the pan 10 can also have varying thicknesses as required to provide sufficient barrier to vapour. 

1. A vapor barrier pan for use in a building structure comprising: a central body having a top edge, a bottom edge, and a pair of side edges extending between the top and bottom edges; a top flange extending from the top edge to engage an upper surface provided by the building structure; a pair of side flanges extending from the side edges for engaging substantially vertical laterally spaced surfaces provided by the building structure; and a tab extending from the central body from the bottom edge for engaging at least one lower surface provided by the building structure.
 2. The pan according to claim 1, further comprising a crease extending through the top flange, the central body, and the tab to enable the overall width of the pan to be adjusted by bending the central body about the crease.
 3. The pan according to claim 2, wherein the crease enables the pan to be bent in a forward direction or a rearward direction.
 4. The pan according to claim 2, wherein the crease is adjacent at least one foldable portion of the central body to allow the width of the central body to be decreased or increased.
 5. The pan according to claim 1, wherein the tab is generally L-shaped to enable the pan to be seated atop an upwardly facing one of the at least one lower surface and engage a forward facing one of the at least one lower surface.
 6. The pan according to claim 5, wherein the tab extends along the forward facing surface sufficient to enable a vapor barrier sheet to be attached thereto.
 7. The pan according to claim 1, further comprising at least one adhesive strip along any one or more of the top flange, side flanges, or tab to provide a seal between the pan and the building structure.
 8. The pan according to claim 1, further comprising a backing comprising an insulative layer within a pocket covered by the pan.
 9. The pan according to claim 1, wherein the upper surface provided by the building structure is a subfloor situated atop a series of joists, the laterally spaced surfaces are provided by adjacent ones of the series of joists, and the lower surface is provided by a sill, the pan covering a joist pocket.
 10. The pan according to claim 9, wherein the sill is supported atop a basement foundation wall.
 11. The pan according to claim 1, wherein the pan is integrally molded from a material which has sufficient strength such that the flanges are self-supporting at right angles to the body and which material is impermeable to moisture.
 12. The pan according to claim 1, wherein the flanges are tapered outwardly to permit stacking of a plurality of pans. 